Claiming harsher sentences, more surveillance and more police and police powers would actually improve safety. The reality is they do not.
I don't know about you, but when I'm driving and I see a police car, if there's little or no other traffic I make sure I'm at or below the speed limit. If I'm in moderate traffic going the speed limit, I wait until the cop is out of sight for a minute or two before trying to pass. If I'm in heavy traffic I'm probably stuck in a pack, so it doesn't matter.
In the first two scenarios, my increased attention to my speed probably has a non-zero improvement in safety for the moment in question.
Back to your original point:
I don't have any citation to back this up, but I've heard that for most crimes, the certainty of being caught is a stronger deterrent than the expected punishment. Unfortunately, "near certainty of being caught" when you break the law is pretty much the definition of a police state. As long as "X" is tolerably low, I would rather live in a country where I have X% chance of being a victim of a particular type of crime in a given year with less survellance than where I have 0.5X% chance with more survellance.